Method of charging ballpoint pens



April 25, 1967 E. J. HENRIKSEN METHOD OF CHARGING BALLPOINT PENS FiledJuly 9, 1964 F. A mm gw W nyvE/vrol? $22252 J Hazard Jen ATTORNEYSUnited States Patent 3,315,437 METHOD OF CHARGHNG BALLPOINT PENS ErnstJ. Henriksen, 1 Alpenstrasse, Lucerne, Switzerland Filed July 9, 1964,Ser. No. 381,390 6 Claims. (CI. 53-37) This invention relates to amethod of charging ballpoint pen reservoirs with a charge of ink and aplug follower means at the free surface of the ink.

While the description will proceed with reference to a ballpoint pen, itis to be understood that the invention is applicable, with equalfacility, to reservoirs of other pens and/ or applicators.

The present-day ballpoint pens employ a rather heavy ink and often anink that dries or hardens on exposure to air. Applicant has devised amethod for preventing such ink deterioration which comprises theprovision of a non-solid follower comprising a plug of suitable materialplaced in the ink reservoir at the free surface of the ink and whichplug follows the ink as it is consumed and keeps the ink surfaceisolated from air in the reservoir. Usually such follower material is agreasy or pulpy mass. Such a follower plug is more fully described inthis applicants prior Patent No. 2,678,634. The follower plug may beplaced in an ink reservoir of capillary dimensions or even in areservoir of greater than capillary diameter and in the latter caseserves the further purpose of preventing flow of the ink out through theopen end of the reservoir when a pen or refill is placed on its side.

Many, if not most, commercial ballpoint pens today employ such afollower as described above and the present invention relates to amanner of efiiciently and inexpensively placing that material in thereservoir. In the manufacture of such pens, and of refills, therefor, anopen-end tube, open at both ends, is charged with a supply of ink byforcing the same into one end thereof in an amount less than thatrequired to completely fill the reservoir. Thereafter, a writing tip isaffixed and secured to the end of the tube through which the ink wasinserted. The writing tip is customarily empty of ink and contains onlyair which would prevent even the commencement of writing and it becomesnecessary to force the ink into the writing tip and to expel anyentrapped air therefrom before the pen is ready for use. Customarily,after assembling the Writing tip to the charged reservoir, the device isplaced in a centrifuge with the Writing tip outermost and thecentrifuging operation causes the ink to flow into and completely fillthe writing tip and any air therein or air trapped in the ink is forcedthrough the body of ink, out through the other end of the reservoir. Itis the present practice to thereafter insert the plug follower mentionedabove into the open end of the reservoir and the processes presentlyemployed add expense and time to the completion of the pen.

According to the present invention a body of the follower material, ofthe proper predetermined volume, is positioned adjacent the open end ofthe ink reservoir when the latter is placed in the centrifuge and uponsubsequent centrifuge action, the previously described expulsion of airis accomplished and at the same time the centrifugal force acting on thefollower material causes the same to move into the open end of thereservoir, to contact the free surface of the ink and to conform to theinner surface of the reservoir in sealing relation thereto. The means bywhich the follower material is placed in the described position will bedescribed in more detail.

It is also within the scope of the present invention to change a penreservoir with ink alone, or with a follower, by the centrifugal methoddisclosed and claimed.

It is, therefore, a principal object of this invention to 3,315,437Patented Apr. 25, 1967 provide a novel method of inserting a fluentmaterial in a pen reservoir.

Another object is to provide a novel method, as set forth above, whereinthe insertion of a plug material is accomplished by centrifugal actionsimultaneously with the performance of a conventional step in making andcharging pen ink reservoirs.

Additional and further objects and advantages will become apparent tothose skilled in the art as the description proceeds with reference tothe accompanying drawings wherein:

FIG. 1 is a side view of one form of ballpoint pen reservoir showing thefollower material in position to be forced into the reservoir;

FIG. 2 is a view similar to FIG. 1 but showing the parts after acentrifuging operation;

FIG. 3 is a fragmentary schematic view of an apparatus for measuringpredetermined quantities of the follower material in a centrifugingapparatus;

FIG. 4 is a view similar to FIG. 3 but showing the parts in differentrelative positions;

FIG. 5 is a detailed sectional view of a modified form of holder for thematerial; and

FIG. 6 is an enlarged detailed sectional view of a further modified formof holder for plural materials.

FIG. 1 shows What may be considered a conventional ballpoint inkreservoir or refill comprising a tubular reservoir portion 2 and awriting tip having a connector portion 4 secured to one end of the tube2 and a tubular writing tip portion 6 carried by the connector 4, andincluding a ballpoint 8. The refill shown in FIG. 1 is merely by way ofillustration since other forms of reservoir may be employed to practicethe present invention. As previously pointed out the tube 2 isconventionally filled with a body of ink 10 by forcing the samethereinto, under pressure, from the lower end of the tube before thewriting tip is installed. Thereafter, the connector 4 is secured to thelower end of the tube and, according to the present practice, theassembly is then placed in a centrifuge and rotated at high speed so asto force ink 10 into the writing tip 6 and to force air upwardlytherefrom through the body of ink 10 and to the exterior of thereservoir.

In the example, shown in FIGS. 1 and 2, a holder device 12 is shownwhich comprises a generally tubular member having a reduced diameterportion 14 terminating in a shoulder 16. The holder device 12 is hollow,open at both ends, and the portion 14 is of a size to be snugly receivedin the open end of the tube 2 with the shoulder 16 abutting the end ofthe tube. Prior to placing the device 12 on the tube 2, the interiorthereof is filled with a suitable non-solid follower plug material 18,which may be of the type heretofore referred to. Obviously, the material18 may be placed in the holder 12 by automatic machinery or otherwise,in a rapid manner suitable for mass production. After the parts areassembled as shown in FIG. 1, the assembly is placed in a centrifugewith the writing tip pointing radially outwardly and upon rotation, thepreviously described removal of air is accomplished and at the same timecentrifugal force acts on the material 18 to cause the same to flowinwardly into the tube 2 into contact with the surface of the ink 10 andto expand in shape to completely engage the inner surface of the tube 2and thus seal the ink against contact by air. Many commercial ballpointpens and refills include a cap member at the open end of the tube 2,which cap member is provided with an opening for the admission of airinto the reservoir to replace the ink as the latter is used. Obviously,the holder 12 may be left in the position shown to serve as such a cap,in which case it may be secured permanently to the tube 2 byindentations (not shown) or in any other suitable manner. In many cases,the. inner end of the passageway through holder 12 may be of reduceddiameter (as shown at 19) to temporarily restrict or control the rate offlow of material 18 into the tube 2. The size of the restriction 19 mustbe chosen according to the consistency of the material 18. \Vhen thematerial 18 is a liquid such as the main ink supply restriction 19 mustbe quite small and may be a plurality of very small openings as shown at21 in FIG. 5.

Likewise the outer end of that passageway may be restricted or partiallyclosed, especially if the holder 12 is to be left on the tube 2 as apermanent cap.

FIGS. 3 and 4 illustrate a slightly differentmanner of providing ameasured quantity of the follower plug material and holding it in theproper position to be centrifuged into a reservoir. In FIGS. 3 and 4,the tubular reservoir 2 and other associated parts of the pen structuremay be identical to those shown in FIGS. 1 and 2 and are so identified.It is to be understood, however, that other forms of reservoir may alsobe used. In these figures, numeral indicates generally a centrifugehaving a rotor 22 provided with holding means 24 designed to receive andhold a reservoir thereon with its writing tip 6 extending radiallyoutwardly and its open inner end pointing inwardly. The centrifuge rotor22 is provided with a central chamber 25 defined by a thick wall 26 andcontaining a supply 28 of the follower material 18. The chamber 25 isdefined by a relatively thick cylindrical wall 26 having openings 30therethrough each of which is radially aligned with a reservoir 2 inthe'holders 24. Each of the openings 30 is of a volume to containexactly the desired quantity of follower material 18. An inner movablewall member .32 is movably mounted within the chamber 25 and is providedwith a plurality of openings 34 therein, which openings may be placed inalignment with the openings 30, as shown in FIG. 3. An outer wall 36 ismovably mounted on the exterior surface of the chamber wall 26 and'islikewise provided with a plurality of passageways 38 therein adapted tobe moved into or out of alignment with the openings 30 and reservoirs 2,as shown in FIG. 4. Each of the passageways 38 is preferably defined bya short nozzle structure 40 integral with the wall 36. The nozzles 40are of such radial extent as to extend to a position closely adjacentthe ends of the reservoirs 2 when the latter are mounted in the holders24.

With the parts in the position shown in FIG. 3, the material 28 may beforced by pressure into the openings 30 to fill the same while the outerwall'36 closes the outer ends of those openings. The filling of theopenings 30 may be accomplished by applying static presure to the massof semi-fluid material 28 or the latter may be caused to flow into theopenings 30 after the centrifuge has started to rotate, by centrifugalforce. In any event, after the openings 30 are filled with the material18, the inner wall member 32 is moved to the position shown in FIG. 4'tointerrupt communication between the openings 30 and the supply chamber25 and thereafter the outer wall 36 is moved to the position of FIG. 4to open the outer ends of openings 30 and provide a flow path therefrominto the upper ends of the reservoirs 2. This all may be accomplishedprior to commencement of rotation of the rotor 22 or it may be doneafter the rotor has started to rotate. In the latter case, more time isavailable for expelling all air from the ink reservoir before insertionof the follower plug. However, even if the parts are brought to theposition of FIG. 4 before rotation commences, the material 18 willremain in the openings 30 until sufficient centrifugal force has beendeveloped to cause the same to flow outwardly and assume the shapes andpositions shown in FIG. 4. Obviously, those skilled in the art may adoptany desired sequence of operation of the parts of the mechanisms shownin FIG. 3, without departing from the spirit of the invention.

It is to be noted that after the centrifuging step, the

amount of follower material 18 in each reservoir is preferably less thanthe amount that would be necessary to completely fill the latter to itsupper end. It is desir= able that the follower plug be initially locatedat leasta short distance inwardly of the open end of the reservoir;

In some instances, it is desirable to provide a ballpoint pen with afollower plug consisting of more than one layer of material, thedifferent layers being of different materials. The present inventionlends itself readilyto the insertion of such multi-layer followersbypermittirig" the easy and economical insertion of the various layersof the follower plug by successive centrifuging steps ifrespective ofthe viscosity or nature of the material of each layer. In someinstances, an intermediate layer may be a very thin fiowable materialand difiicult to in sort in the reservoir by conventional or priormethods.

FIG. 6 shows an alternative method of introducing plural layers ofmaterial into the pen reservoir.- As shown, a holder for the material,corresponding general= 1y to the holder '12 of FIG. 1, consists of twoseparate sections 50 and 52. The section 52 has a reduced end portion 58telescopically received in the outer end of the portion 59. The portion50 has a reduced end por tion 60 adapted to be telescopically positionedand held within the open end of the pen reservoir 2 (not shown in FIG.6). As shown, the section 50 has an opening 62 therein whereas thesection 52 has a restricted opening 64 in the lower end thereof. Thus, amaterial 5-6 may be loaded into the seetion52 and a second material 54loaded into section 50. The sections are thereupon assembled in themanner shown and placed in the open end of the pen reservoir and theentire assembly then placed in a centrifuge machine to cause bothmaterials 54 and 5-6 to enter the reservoir. Obviously, the capacitiesof the sections 50 and 52 will depend upon the purpose and material ofthe materials therein. The material 54 could be the main ink supply andm aterial'56 a suitable follower plug. On the other hand both materials54 and 56 could be different components of a multilayer follower;Preferably, the opening 64 is more restricted than the opening 62 sothat the material 54 will enter the pen reservoir before the material 56begins to flow. The size of the openings 62 and 64 will, of course,depend upon the viscosity or consistency of the particular mate rials inthe corresponding sections of the holder. By making opening 64 morerestricted, the discharge of the material 56 is thus delayed untilmaterial 54 is discharged On the other hand the size of the restrictionsmay be so calculated and related to their respective materials so thatmaterial 54 will discharge at one particular speed of the centrifuge andthe material 56 will then be dis charged only at a higher speed.Obviously, many other modifications will be apparent to those skilled inthe art.

Obviously, the capacity ofholder 12 or openings 3t? would be greaterthan shown, in those instances Where the present invention is used tocharge a pen reservoir with its main ink column. a

The holder 12 of FIGS. 1 and 5 and the holders 50 and 52 of FIG. 6 areof a material having low afiinity for the materials 18, 54, or 56 sothat it will clean itself during the cen-trifuging step. Polyethyleneand poly propylene plastics are very good materials for many inks andgreases.

While a limited number'of specific embodiments have been described, itis to be understood that the same are merely illustrative of theprinciples involved and that the invention may be practiced by otherapparatus or means, all within the scope of the appended claims.

I claim:

1. The method of charging an open ended pen reservoir with fluentmaterial, comprising the steps of: measuring a quantity of said fluentmaterial, less than the quantity necessary to fill said reservoir;centrifuging said reservoir with said open end extending radiallyinwardly; and simultaneously positioning said measured quantity of saidfluent material adjacent said open end and aligned therewith wherebysaid centrifuging step causes said measured quantity of fluent materialto enter said open end and conform to the inner periphery of saidreservoir leaving empty a portion of said reservoir, at said open end.

-2. The method of charging an open ended pen reservoir with ink and anon-solid follower, comprising the steps of: placing a body of fluidmaterial, including a column of ink in said reservoir to a leveladjacent but spaced inwardly from said open end; centrifuging saidreservoir and fluid material with said open end extending radiallyinwardly; and simultaneously positioning a body of non-solid followermaterial adjacent said open end and aligned therewith whereby saidcentrifuging step simultaneously expresses air from said reservoir andcolumn of ink and causes said body of follower material to enter saidopen end, engage the adjacent end of said body of fluid material andconform to the inner periphery of said reservoir.

3. The method of claim 2 including the step of limiting the size of saidbody of follower material to a size insuflicient to fill said reservoirto the open end thereof.

4. The method of claim 2 wherein said step of positioning said body offollower material adjacent said open end is performed by placing thesame in an open-ended generally tubular holder and inserting a portionof said holder in the open end of said reservoir, to be supportedthereby.

5. The method of claim 4 including the further step of securing saidholder to said reservoir to serve as a cap therefor.

6. The method of claim 2 wherein said step of positioning said body offollower material adjacent said open end is performed by establishing asupply of said follower material, establishing a measuring zone ofpredetermined volume adjacent said open end, forcing follower materialfrom said supply into said zone to fill the same, isolating said zonefrom said supply, and then establishing communication between said zoneand said open end.

References Cited by the Examiner UNITED STATES PATENTS TRAVIS S.MCGEHEE, Primary Examiner.

2. THE METHOD OF CHARGING AN OPEN ENDED PEN RESERVOIR WITH INK AND ANON-SOLID FOLLOWER, COMPRISING THE STEPS OF: PLACING A BODY OF FLUIDMATERIAL, INCLUDING A COLUMN OF INK IN SAID RESERVOIR TO A LEVELADJACENT BUT SPACED INWARDLY FROM SAID OPEN END; CENTRIFUGING SAIDRESERVOIR AND FLUID MATERIAL WITH SAID OPEN END EXTENDING RADIALLYINWARDLY; AND SIMULTANEOUSLY POSITIONING A BODY OF NON-SOLID FOLLOWERMATERIAL ADJACENT SAID OPEN END AND ALIGNED THEREWITH WHEREBY SAIDCENTRIFUGING STEP SIMULTANEOUSLY EXPRESSES AIR FROM SAID RESERVOIR ANDCOLUMN OF INK AND CAUSES SAID BODY OF FOLLOWER MATERIAL TO ENTER SAIDOPEN END, ENGAGE THE ADJACENT END OF SAID BODY OF FLUID MATERIAL ANDCONFORM TO THE INNER PERIPHERY OF SAID RESERVOIR.